1. Field of the Invention
The present invention relates to a disk apparatus for write data on, and/or read data from, a disk cartridge enclosing a disk-type data storage medium such as an optical disk or a magnetic disk.
2. Description of the Related Art
Disk-type data storage mediums have already been widely spread in the society, for example, CDs, DVDs and the like usable for writing or reading with an optical beam, flexible disks and the like usable for writing or reading with a magnetic force, and MOs, MDs and the like usable for writing or reading with an optical beam and a magnetic force. Especially rewritable mediums such as DVD-RAMs, MOs and the like are stored in a cartridge shown in, for example, Japanese Laid-Open Patent Publication No. 9-153264 for protecting the data stored thereon. Herein, the term “disk cartridge” refers to a cartridge enclosing a disk-type data storage medium.
FIG. 24 schematically shows a structure of a disk cartridge disclosed in Japanese Laid-Open Patent Publication No. 9-153264. As shown in FIG. 24, a disk cartridge 100 encloses a rewritable disk 10 and includes a support base 101 acting as an external housing.
The support base 101 has a window 101w each in a top surface and a bottom surface for allowing means for rotating the disk 10 such as a disk motor and means for performing data writing and/or reading to enter the support base 101 and approach the disk 10.
The support base 101 also has an inner wall for positioning the center of the disk 10 and rotatably holding the disk 10 while saving a clearance for the disk 10.
The disk cartridge 100 includes a shutter 103 folded in a C shape for covering the windows 101w formed in the top surface and the bottom surface and holding the support base 101 to protect surfaces of the disk 10 exposed to the windows 101w. 
The shutter 103 is capable of translating in the direction represented with arrow P shown in FIG. 24, and is loaded by a spring in the direction of closing the windows 101w. In this manner, the disk cartridge 100 is structured so as not to expose the disk 10 unless an external force is applied.
For writing data on, and/or reading data from, the disk cartridge 100 by a disk apparatus (not shown), the cartridge shutter 103 is moved in the direction of arrow T to expose the disk 10 in order to clamp the disk 10 and allow the writing and/or reading means to approach the disk 10. At this point, the movement of the disk cartridge 100 in the direction of arrow Q to enter the disk apparatus is utilized to engage a projection 104a of a shutter opener 104 with a notch 103a of the shutter 103. As the disk cartridge 100 is moved in the direction of arrow Q, the shutter opener 104 is pivoted in the direction of arrow R around a pivoting center 104b, which, in turn, moves the shutter 103 in the direction of arrow T.
In order to catch a disk or allow an optical head to access the entire data storage surface of the disk, a conventional disk cartridge as the disk cartridge disclosed in Japanese Laid-Open Patent Publication No. 9-153264 needs to have a window for such purposes in an area from a center to an edge of the cartridge. In a disk cartridge of this structure, the shutter moves linearly with respect to the housing of the cartridge. Therefore, the disk cartridge needs to have an area to which the shutter is retracted when the shutter is opened. For these reasons, the size of the window depends on the external size of the cartridge. It is very difficult to design a small cartridge having a large window. This causes a problem that in a compact device or a disk video camera using a small cartridge, the size of the optical head is restricted.